Spiral point tap, also known as bull nose taps or gun taps, usually only used for through holes processing.
The ratio of length to diameter can reach 3D~3.5D, chips are discharged forward ahead of the tapping direction. The cutting torque is small, surface quality of the processed thread is high. Its core size design is relatively large, the strength is good enough to withstand large cutting forces. Performance is good when processing non-ferrous material, stainless steel. 2P is use for blind holes, and 4-6P for through holes. As long as the bottom hole is deep enough, a longer chamfer (lead) should be used as far as possible, so that there are more teeth sharing the cutting load and a longer tool life.